One person was airlifted to hospital from the scene in critical condition.
They later died in hospital, police announced yesterday.
Posts on social media confirm the crash took place during the race, with those involved in the event sending condolences.
“Very sad times when we lose a fellow rider, thinking of their loved ones,” a commenter said.
“It was a beautiful day with lots of enthusiastic people. Very sad outcome. Condolences to family and friends,” one wrote.
“Omg so shocked, I rode the fun ride yesterday, these are my local roads. Aroha to the family of the rider and to the responders,” another said.
USO Bike Ride, a Pacific cycling network, took to social media to offer its condolences.
“We send our prayers, alofa and condolences to the family of the rider who passed away following an accident between x2 riders at the Wairarapa Charity Funride yesterday.
“We keep the surviving rider and his family in our prayers too – a sad day for the cycling community,” the organisation wrote.
The event, which started in 1995, originally operated under the banner of the Wellington Veterans Cycling Club, but has since become an annual standalone charity race, organised by the Rotary Club of South Wairarapa.
The weekend’s ride raised funds for The CatWalk Trust, which funds research for spinal cord injuries.